Eli5 – what do they use to preserve railroad ties, utility poles etc vs stuff available to common mortals at big box stores?

Question

Most stuff in the stores says 1-2 years decks, 2-4 years vertical. Railroad ties, utility poles etc last decades… what do they use? Is it only available commercially?

In: 1

Answer 1

Railroad ties and utility poles are not made for humans to be around them. Firstly that means that they can use a lot of creosote. It smells horrible and is actually poisonous. So you do not want much of it in your wooden decking. But it also means that when the wooden ties and utility poles and such start to wear down and get ugly producing splinters and such nobody is around to care. People only start to care once that top layer of decay gets deep enough to cause structural issues. However when your wooden deck starts looking ugly and your kids start get splinters from it you want to replace it as soon as possible, even if it may be structurally sound for a few more decades.